Sawing apparatus



E. DE V. TOMPKINS.

SAWING APPARATUS.

APPLICATION FILED JUNE 11, 1918.

1 ,349fi98, Patented Aug. 17, 1920.

3 SHEETSr-SHEET 1.

E. DE V. TOMPKINS.

SAWING APPARATUS.

APPLKCATION FILED JUNE 11, I918.

Patented A11 H, mm

3 SHEETS-SHEET 2.

E. DE V. TOMPKINS.

Patented Aug. 17, 1920.

3 SHEETSSHEE'I 3.

UNITED STATES EDWARD DE VOE TOMIKINS, OF NEW YORK, N. Y.

SAWING *APPARATUS.

Specification of Letters ma.

Patented Aug. 17, 1920.

Application filed June 11, 1918. Serial No. 239,355.

To all whom it may concern:

Be it known that I, EDWARD DE Von TOMPKINS, a citizen of the United States, residing at New York, county of New York, and State of New York, have invented certain new and useful Improvements in Sawing Apparatus, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

This invention relates to improvements in sawing apparatus. and more especially to power driven apparatus of this type as set forth in United States Patent No. 1,215,431,

granted to me February 13th, 1917.

The object of the present invention is the provision of a saw of this type which shall be more compact in form, more efficient in operation, and one in which the eccentric pull upon the saw blades shall be decreased to a minimum. The invention also includes many detail improvements whereby the con struction is greatly simplified and improved.

A full understanding of the invention will now be given by the following detail description of a construction embodying the same. taken in connection with the accompanying drawings illustrating the invention in a preferred form, and the features thereof forming the invention pointed out in the claims.

In the drawings- Figure 1 is a side elevation partly in section of the improved saw.

Fig. 2 is a horizontal section taken on the line .2-2 of Fig. 1.

Fig. 3 is a vertical sectional view of controlling end of the saw. k

Fig. 4 is a section on the line 4-4 of Fig. 3, showing the distributing valve chamber in detail.

Fig. 5 is a section on lines 5-5 of Figs.

3 and 4, showing the distributing valve.

Fig. 6 is a section on line 6-6 of Fig. 5,

showing that cylinder head and its ports.

Fig. 7 is a vertical sectional view of the other end of the saw.

Fig. 8 is a section on line 8\8 of Fig. 3.,

Fig. 9 is a section on line 9--9 of Fig. 3.

Fig. 10 is a section on line 10-10 of Fig. 3.

Fig. 11 is a detail view of the saw blades and their guides.

Referring to the drawings, the saw is of the frame saw type in which a plurality of juxtaposed blades are supported in the frame work and adapted to reciprocate simultaneously in opposite directions. The saw frame consists of two handles 30, 31, provided with inwardly extending projections 32, 33, connected by a flat tie plate 34. A hollow compression member 35 is held in pivotal relation to the handles 30 and 31 by couplings 36 screwed upon their respective ends of the compression member 35 and pivoted to the handles by pivot bolts 37.

Suitable means is provided at both ends for adjusting the alinement of various parts of the saw blades and frame, consisting in the present instance, of turnbuckles 38 pivoted respectively to the couplings 36 and the handles 30 and 31 respectively.

A plurality of saw blades, in the present instance two, A and B, are provided, having teeth of any suitable type but preferably of the type shown in the drawings, in which each blade is provided with alternating cutting or peg teeth a, and chisel or M-teeth b. In order to prevent interference between the teeth of one blade with those of the other, and at the same time give the necessary set for cutting the width of the kerf, the cutting or peg teeth a are set oppositely to the set of the same teeth of the other blade, while the chisel or M-teeth b of both blades are straight, that is, they lie in the same plane as that of their respective blades. It will thus be seen that when the two blades which are tensioned to reciprocate in the same kerf are put in operation, the same effect as that of a single bladed saw of either the reciprocating or circular type will be obtained.

Suitable means are provided for reciprocating the saws in opposite directions alternately, consisting of power mechanism arranged to be operated by fluid pressure, in the present instance, by compressed air. Preferably this power mechanism is of the form illustrated in the drawings, and this specific form will now be described.

Ateach end of the saw blades, and secured to the handles, are located twin cylinders 39, 40'and 41, 42. Preferably these cylinders are mounted concentrically, asshown in the drawings, and are provided respectively with pistons 43, 44 and 45, 46, the pistons 44, 46 having respectively eccentrically mounted piston rods 47 and 48 secured to plates 50 and 53. In like manner the pistons 43, 45 are each provided respectively with a pair of eccentric piston rods 51 52,

secured to. plates 49, 54. The saw blade A has its ends secured to the plates 53 and 54 respectively, while the blade B has its ends secured to the plates 49 and 50 respectively. Counter-sunk screw bolts are used as the securing means.

Suitable means are provided for guiding the saw blades which preferably takes the form shown in Fig. 11, in whiclr the plates 49, 50, 53 and 54 are each provided with a dove-tail groove 55 coacting with one of two dove-tail shaped guide rails 56 secured by screws to the extensions 32, 33 of the handles 30 and 31.

For convenience the concentric cylinders will be described in pairs, and the pair attached to the controlling handle 30 will be described first, in connection with suitable passages, ports, and controlling mechanism contained in the controlling handle 30.

The controlling handle 30 is provided with an inlet spud 57 adapted for connection to suitable flexible piping 58 for the induction of compressed air to the apparatus, and contains an inlet passage 59 in communication with a supply valve passage 60 through a port 61. The outer and inner ends of the concentric cylinders 39 and 40 are connected with the valve passage 60 as follows: At the outer end of the cylinders there is located a distributing valve chamber 62, which is provided with an inlet passage 63 connecting with a port 64 n the supply valve passage 60, the port 64 in the present instance being otfset slightly from the port 61 above it connecting the supply valve passage 60 with the inlet passage 59. The inner ends of the cylinders 39 and 40 are in communication with each other through a plurality of ports 65 in the wall of cylinder 40. Communication is established between cylinder 39 and supply valve passage 60 through port 66, and passages 67 and 68 in handle 30 and passage 69 through the inner cylinder head 70. The passage 68 is controlled by a suitable downwardly opening check valve 71 shown in the drawing as a ball check valve.

For controlling the supply of compressed air to the apparatus, a suitable hand-operated supply valve is provided consisting of an elongated piston slide valve 72 mounted in valve passage 60 upon valve rod 73 provided With a valve rod head 74 which operates within an open chamber 7 5. The valve rod head 74 is provided with sidewise extending pins 76, 77 co-acting with slots formed in arms 78, 79 carried by handle 80 pivoted to the handle 30 on pivot pin 81.

Between the distributing valve chamber 62 and vthe cylinders 39, 40 there is secured a cylinder head 82 provided with combined inlet and outlet passages, 1, 2 and valve controlling passages, 3, 4, for the respective cylinders. The valve chamber 62 is provided with suitable ports 5, 6, 4 and 8 registering respectively with the passages l, 2, i and 4, and contains a distributing valve 2 which may be of any suitable type, but preferably is of the ported piston slide valve type, and in the present instance is entirely automatic, being actuated by compressed fiuid from either cylinder 39 or 4 as the case may be. This distributing valve 20 is provided with two annular ports 9, 19. which act to connect the ports 5; (i with the inlet passage 63 or with the discharge passage 11, having right hand and left hand discharge ports 12, 13 in the valve cylinder 62. Preferably the discharge passage 11 is provided with an extension 91 extending to within a short distance of the saw blades, so that the exhaust may be utilized to cool and lubricate the saws and to remove the saw dust.. The distributing valve is also provided with annular ports 1-1, 15, registering respectively with the ports T. 8. and passages 16, 17 are provided connecting the annular ports 14, 15 with their res )ective valve chamber ends. Each of the cylinders 39 and 40 at the distributing valve chamber end is provided with a slot 18, 19, connecting respectively with passages 3, 4, and of sufiicient length to overlap the respective pistons when they are approximately at or near the end of that stroke in which they move toward the distributing valve chamber end of the cylinders.

The cylinders 41 and 42, at the opposite end of the saw, are suitably secured to the handle 31, and cylinder 42 is provided at its inner and outer end, respectively. with ports 83, 84, establishing communication between the two cylinders. The outer ends of the cylinders are also in communication with the atmosphere through a passage S5 connecting with the interior of the cylinder -12.

The handle 31 is provided with passages 86, 87, which latter passage is connected to the cylinder 41 by a passage 88 through the cylinder head 89. Passage 8? is controlled by a suitable downwardly opening check valve 90, preferably of the ball check type. as in the case of check valve 71. These check valves consist of a valve cage comprising a cylindrical shell 92 provided with upper and lower cap plates 93, 94. between which the ball valve 90 operates. (a p plate 93 has a suitably combined port and valve seat 96, centrally located, and plate 94- is provided with a corresponding seat 97 for the ball valve when open. This seat 97 is surrounded by a plurality of ports 96 to allow passage of the compressed air through the structure. For the purpose of securing the parts in position, a locking plate 99. provided with an air passage 100, is screwed into the handle 30 or 31, as the case may be. and bears against the lower cap plate 94-.

The compression member 35 is hollow, as

previously stated, and the coupling devices at each end are provided with a suitable passage 102 through one leg thereof communicating with the passage 101, through the pivot bolt 37, which connects with either the passage 86 in handle 31 or with the passage 67 in handle 30, as the case ma be.

he operation of the device is as follows: U on depressing the controlling handle 80 t 1e initial movement of supply valve 72 uncovers supply port 61, allowing compressed air to pass through port 66, passages 67, 68, check valve 71, passage 69 and ports 65 to the inner sides of pistons 43, 44. Simultaneously the compressed air will ass through the compression member 35 an its couplings 36 'at each end thereof, through passages 86, 87, check valve 90, passage 88 and ports 83 to the inner sides of the pistons 45 and 46, so that substantially the same pressures exist on the inner sides of all the pistons and the pressures on the inner sides of the pistons 45, 46 oppose the pressures on'the inner sides of the pistons 43, 44.

If the areas of all four pistons are equal, no movement will result from the admission of air to the innersides of the pistons, the opposing pressures merely straining the blades tightly. In practice, however, it is well to have the areas of the annular pistons slightly greater than the areas of the circular pistons so that the annular pistons will move to the outer ends of their respective cylinders in order to properly osition the saws for starting operation. owever, the difference of these areas may be only just sufficierit to overcome the friction of the moving parts. Hence it may be said that the pressures against the inner sides of a pair of connected pistons substantially balance each other. In fact, the pistons may all be of equal area and therefore the pressures exactly balanced, if care be taken to have the saws properly positioned in beginning operations. That is, if, when the saw device is not in use, it should be jarred and, as a result, the pistons and saws be moved out of their proper relative positions, they may be moved by hand to their proper positions before admitting the air pressure.

It will be seen that at this time the pistons are subject to substantially balanced pressures as follows :--The inner sides of all the pistons are subject to compressed air of the same pressure, The outer sides of pistons 45 and 46 are subject to atmospheric pressure admitted through passage 85 and ports 84 connecting the cylinders 41 and 42, and the outer sides of pistons 43 and 44 are balanced and balance the above pressures as cylinder 39 has been exhausted to the atmosphere through valve 20 and cylinder 40 contains air which has been expanded to atmospheric pressure in driving the piston 44 to Attention is now called to Figs. 3, 4 and 5 in which the relative positions of the distributing valve 20 and the piston 43 are shown as the piston 43 is moved to starting position and immediately before the shift of valve 20 for delivery of unbalanced pressure against the outer side of piston 43. As piston 43 approaches this position passage 18 is uncovered and allows a portion of the compressed air between pistons 43, 44 to escape through ports 3, 7 and 14 to passage 16 and move valve 20 to its opposite position in whlch annular port 9 connects port 6 with left hand discharge port 13 for discharge of expanded air from cylinder 40, and annular port 10 connects inlet passage 63 with port 5 for delivery of the unbalanced air pressure against piston 43.

A further movement of the hand operated supply valve 72 now establishes communication between the inlet passage 63 and the supply valve passage 60 andthe compressed air, WlllC-ll is the unbalanced pressure, acts upon the outer side of aiston 43 driving the piston to the right, w iich movement causes the check valve 71 to close, and the piston 44 to move toward the left dragging the saw blade A and piston 45 with it. When piston 45 starts its movement, the check valve 90 closes and the compressed air between pistons 45 and 46 causes the piston 46 to move to the right dragging with it the saw blade B. These piston pressures are so balanced that the initial movement of the piston subjected to the unbalanced pressure of the live air produces an instantaneous movement of the other pistons and the saw blades.

At or near the completion of the outward stroke of the piston 44 and the inward movement of the piston 43, the compressed air within cylinder 39, between pistons 43 and 44, will escape through slot 19, passage 4 and port 8 to the annular port 15 and its passage 17 in the distributing valve 20, to that end of the valve chamber, causing the distributing valve to move toward the right, to the position shown in Figs. 4 and 5, whereupon the cylinder 39 will be connected to the right hand discharge port 12 through annular port 10 of the distributing valve, )ort 5 and passage 1, thereby allowing the exhaust of the expanded air upon the return stroke of the piston 43. At the same time the movement of the valve to the right, will connect the port 6 and passage 2 with the inlet passage 63 through annular port 9, thereby subjecting the piston 44 to unbalanced pressure and reversin the movement already described. Before the piston 44 begins its driving movement, however, the check valve 71 will open momentarily in order to replenish the space between the pistons 43, 44 with compressed air to take the place of that which has been allowed to escape in order to shift the distributing, valve 20.

vIt will be seen that the invention consists in providing a pair of saw blades adapted to reciprocate in the same kerf with a pair of main cylinders at one end and a pair of supplementary cylinders at the other end. Suitable means consisting of passages, ports and check valves for maintaining a condition of substantial pressure balance on the pistons, and an automatic distributing valve in connection with the main cylinders for alternately subjectin the main pistons on their outer sides to the action of an unbalanced pressure, to cause the saw blades to move simultaneously in opposite directions.

By the use of this arrangement, which enables me to use a single distributing valve to control the unbalanced pressure, I am enabled to eliminate all necessity of synchronizing the movement of a plurality of valves, which was necessary in my former construction. It will also be observed that by the use of concentric cylinders at each end of the saw, I am enabled to greatly reduce the eccentric pull upon the saw blades, as this disposition allows the placing of the eccentric piston rods much nearer to the center lines of the cylinders.

It will be understood that the invention is not to be limited to the construction shown and described, as many changes may be made therein without departing from the invention as defined by the claims.

An important feature of the invention consists in providing the pivotal connections 37 of the compression member 35 to the parts 32 and 33 and the pivotal connection of the tension member 34 to said parts 32 and 33, all of the pivotal connections being in line. This makes it possible to construct the parts separately and assemble them with certainty of proper alinement of the cylinders and uides. b A further feature of importance is that the pistons are not fixed on their rods, but are capable of sliding in one direction thereon. In the construction illustrated, the ends of the rods are enlarged as shown in Fig. 3, the holes in the pistons being correspondingly formed so that the pistons are free to move relative to their rods in one direction only. By this construction it is impossible to bring any compressive stra1n on the rods or saw blades, and hence no buckling of them is possible.

Since the device is capable of use for underwater work the passage at the outer end of the supplementary cylinders may be provided with a suitable outward opening spring valve, as shown in Fig. 7, Which, while allowing the escape of air, will not permit the water to enter the outer ends of the supplementary cylinders. 7(

What is claimed is:

1. The combination with a plurality of reciprocating saw blades adapted to work in the same kerf, of substantially pressurebalanced mechanism connected to said 7t blades, and means for directing an unbalanced pressure to said pressure-balanced mechanism to cause said blades to move simultaneously in opposite directions.

2. The combination with a plurality of cutting blades adapted to work in the same kerf, pistons attached to each end of said blades, means for maintaining substantially a pressure balance upon said pistons, and a distributing valve for directing an unbalanced pressure against one of said pistons to cause the blades to move simultaneously in opposite directions.

3. The combination with a plurality of reciprocating cutting blades adapted to work in the same kerf, pistons attached to the ends of said blades, means for maintaining substantially a pressure balance upon said pistons, and an automatic distributing valve for directing an unbalanced pressure to one of said pistons to cause the blades to move simultaneously in opposite directions.

4. The combination with a pair of saw blades arranged to work in the same kerf, 10C of substantially pressure-balanced means for straining said blades, and means for directing an unbalanced pressure to said pressurebalanced means to cause the blades to move simultaneously in opposite directions.

5. The combination with a pair of saw blades arranged to work in the same kerf, of substantially pressure-balanced means for straining said blades, and a distributing valve for directing an unbalanced pressure to said pressure-balanced means to cause the blades to move simultaneously in opposite directions.

6. The combination with a pair of cutting blades adapted to work in the same kerf, of main and supplementary cylinders, pistons within said cylinders and connected to the respective blades, means for maintaining opposing pressures against the pair of pistons connected to each.blade, and means for di- 12 recting an unbalanced pressure against one or the other of said main pistons to cause said blades to reciprocate simultaneously in opposite directions.

7. The combination with a pair of cutting blades adapted to work in the same kerf, of main and supplementary cylinders, pistons within said cylinders and connected to the respective blades, means for maintaining opposing pressures against the pair of pistons connected to each blade, and a distributing valve for directing an unbalanced pressure against one or the other of said main pistons to cause said blades to reciprocate simultaneously in opposite directions.

8. The combination with a pair of cuttin blades arranged to work in the same ker each blade having pistons at opposite ends and main and supplementary cylinders in which said pistons work, of means for maintaining opposing pressures against the pair of pistons connected to each blade, and valve means for directing an'unbalanced pressure to one or the other of said main cylinders to cause the blades to move simultaneously in opposite directions.

9. The combination with a pair of saw blades arranged to work in the same kerf, of main cylinders at one end of the blades and supplementary cylinders at the opposite ends of the blades, pistons within said cylinders connected to the blades, means arranged to maintain substantially balanced pressures upon said pistons, and valve means for directing an unbalanced pressure against first one, and then the other of said main pistons, to cause the blades to move alternately and simultaneously in opposite directions.

10. The combinationwith a pair of saw blades arranged to work in the same kerf, of a pair of main cylinders and a pairof supplementary cylinders, pistons within said cylinders connected to said blades, means for maintaining opposing pressures upon said pistons, and a distributing valve arranged to direct an unbalanced pressure against first one and thenthe other of said main pistons to cause the saw blades to move alternately and simultaneously in opposite directions.

11. The combination with a pair of cutting blades arranged to reciprocate in the same kerf, of concentric main cylinders and concentric supplementary cylinders, pistons within said cylinders connected to said blades, means for maintaining opposing pressures upon said pistons, and valve means for directing an unbalanced pressure against one or the other of said main pistons.

12. The combination with a pair of saw blades arranged to reciprocate in the same kerf, of concentric main cylinders and concentric supplementary cylinders, pistons within said cylinders connected to said blades, means for maintaining opposing pressures upon said pistons, and a distributing valve for directing an unbalanced pressure against one or the other of said main pistons. y

13. The combination with a pair of saw blades arranged to reciprocate in the same kerf, of concentric main cylinders and concentric supplementary cylinders, pistons within said cylinders connected to said blades, means for maintaining opposing pressures'upon said pistons, and an automatic distributing valve for directing an unbalanced pressure against one or the other of said main pistons.

14. The combination with a pair of saw blades adapted to work in the same kerf, of substantially pressure-balanced mechanism for reciprocating said blades, means for directing an unbalanced pressure to said pressure-balanced mechanism to cause said blades to move simultaneously in opposite directions, and a hand operated valve controlling the supply of pressure to the pressure-balanced mechanism for maintaining the balance and to the means for directing an unbalanced pressure to the pressure-balanced mechanism.

15. The combination with a pair of saw blades adapted to work in the same kerf, of main cylinders at one end of the saw blades, supplementary cylinders at the other end, substantially pressure-balanced pistons within said cylinders and connected to the saw blades, a distributing valve for directing an unbalanced pressure against one or the other of said main pistons, and a supply valve arranged to supply said cylinders with balancing pressure in its initial opening movement and to supply unbalanced pressure to the distributing valve in its final openin movement.

16. he combination with a pair of saw blades adapted to work in the. same kerf, of concentric main cylinders, concentric supplementary cylinders, the concentric main cylinders being in communication at their inner ends, pistons within said cylinders connected to said blades, a distributing valve chest across the outer ends of said main cylinders, a distributing valve within said valve chest, and means consisting of slots in said main cylinders and ports and passages in said distributing valve and its chamber, whereby at or near the endof the discharge stroke of one of said main pistons a portion of the compressed air in the connected ends of the main cylinders between the two main pistons is passed around said discharging piston for the purpose of shifting said distributing valve to reverse the movement of said main pistons.

17 The combination, with a pair of cutting blades arranged to Work in a single kerf, of piston rods connected to said blades, pistons connected to said rods so as to be free to move inwardly relative to the rods substantially as described, cylinders on which said pistons move, means for supply ing opposing pressures to the pistons, and means for supplying an unbalanced pressure to cause the blades to be reciprocated.

18. The combination, with a pair of cut ting blades arranged to work in a single kerf, main and supplementary cylinders, pistons in said cylinders and connected to the respective blades, and means for admi ting pressure to the cylinders to cause the reciprocation of the blades, guide members connected to each cylinder for guiding the saws, and a tension member and a compression member pivotally connected to the respective 'uide members, the pivotal points being in Tine, whereby the alinement of the guides and cylinders is obtained and maintained.

In testimony whereof, I have hereunto set my hand.

EDXVARD DE VOE TOMPKINS. 

